In this study we are trying with the help of portfolio in teacher training and the diagnosis of the learning group concerning their skills in translation from German to Turkish, to show the documentation of the learning process. The portfolio provides a good overview about the performance of the students and it also prepares a basis for assessment. A growing self-awareness of students can be achieved through implementing the portfolio-method. The students should collect and reflect the most important materials and practices leading to key terms of the seminar. It is more than an assessment method it is a surrounding of learning. The work with portfolio has an influence on teaching, learning and assessing. As in detail, this is dependent on the aims and other characteristics of the models which take the portfolio work as a basis. The portfolio provides us a big advantage for the support of the cultural reflection. We can observe the process of the growth of knowledge step by step, because the measurement of the development in a determined period allows us either a written work or a Multiple Choice Test. In this sense we can look at the portfolio as an assessment instrument of a process.